Colorado: After a wet August, Summit County precip ahead of average for the year

A monsoonal flow brought steady showers to Summit County in August. bberwyn photo.

Moisture above average for the year to date

By Bob Berwyn

FRISCO — An extended monsoon season lifted August precipitation in Breckenridge to well above average, as weather-watcher Rick Bly tallied 4.22 inches of water for the month. The average rainfall for August is 2.26 inches; August 2013 was the wettest August since 1984.

“We had a good month for precipitation,” Bly said, adding that the rainfall often came at night, when it’s even more beneficial because it has a chance to sink into the ground before evaporating.

All in all, the 2012 water year has been up and down, with a “desperately dry October and November, according to Bly, followed by a so-so early winter and a gangbusters spring, with drought-busting snows in April and May.

Last month’s rainfall also pushed the year-to-date total to above average, at 19.38 inches compared to the average 16.83 inches. Even if September ends up being very dry, Breckenridge will end up the water year (Oct. 1 – Sept. 30) above average, he said.

Unfortunately for skiers, there’s no correlation between late summer rainfall and winter weather, even though rumors are flying that it will be an early and big winter. Bly and other weather experts said there’s no statistical evidence linking September precipitation with any seasonal trends.

In fact, the wettest September on record, back in 1961, was followed by a very dry early winter and below-average snowfall for the rest of that winter.

In Breckenridge, September is the third-driest month of the year, with precipitation averageing just 1.45 inches. Even the wettest September on record (1961) brought just 3.74 inches of precipitation. a lot of as snowfall. The early blizzard in that year delivered more than 50 inches of snow.

Precipitation in August was also above average in Dillon, where weather observers with Denver Water tallied 2.13 inches for the month (average 1.77 inches). There was measurable precipitation on all but 12 days of the month at the Dillon site, with 0.34 inches on Aug. 5, the wettest day of the month.

Temperatures at Dillon were very close to normal for the month, with the average daily maximum high registering 72.6 degrees, compared to the average 72.5 degrees. Nighttime low temps were slightly above average, at 37.8 degrees, compared to the average of 36.0 degrees.

The warmest day of the month was Aug, 20, at 80 degrees. Nighttime lows dropped to or below freezing three times in the middle of the month, bottoming out at 31 degrees on Aug. 14.

September is a transition month, with average temperatures falling quickly as the nights turn longer than the days. The average daily high in September is 66.2 degrees and the average low dips to 28.7 degrees. July and August are the only months when average lows are above freezing at the Dillon site.